Adaptive Streaming of Geometry-Based Point Clouds

Abstract

Systems, methods, and means are disclosed for receiving content related to a geometry-based point cloud. A client device may receive a Media Presentation Description (MPD) file from a content server. A set of preselection elements may be identified from the MPD file. One or more adaptation sets associated with at least one preselection element of the set of preselection elements may be identified. The adaptation set may be indicated by an attribute associated with one of the preselection elements. A Geometry-Based Point Cloud Compression (GPCC) tile identifier associated with a viewport may be determined. The GPCC tile identifier may be determined based on a received first descriptor in the MPD file. One or more adaptation sets associated with the GPCC tile identifier may be selected using a second descriptor. Point cloud components associated with the selected one or more adaptation sets may be requested. The point cloud components may be received.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 042,481, filed Jun. 22, 2020, and U.S. Provisional Patent Application No. 63 / 084,758, filed Sep. 29, 2020, the disclosures of which are hereby incorporated by reference in their entirety.

Background Art

[0002] Video coding systems can be used to compress digital video signals to reduce, for example, the storage capacity and / or transmission bandwidth required for such signals. Examples of video coding systems can include block - based systems such as wavelet - based systems, object - based systems, and / or block - based hybrid video coding systems. Video coding systems can support the coding and storage of point clouds. However, these systems may lack a sufficient mechanism to support streaming point cloud data over a network.

Summary of the Invention

[0003] Systems, methods, and means are disclosed for adaptive streaming of visual media content, such as geometry-based point clouds. Elements, attributes, and metadata associated with point cloud components may be signaled, for example, to enable a streaming client to identify point cloud streams and component substreams of these point cloud streams in a media presentation descriptor (MPD) and to enable the streaming client to select versions of the point cloud and / or point cloud components, for example, based on client support. In embodiments, a streaming client may utilize guidance (e.g., instructions signaled in an MPD file) to make decisions regarding various representations of the point cloud content. For example, the instructions may indicate which set of representations across various point cloud components constitutes a particular quality level. Components of the point cloud content may be divided into multiple tiles or tile portions. A client may stream specific tile portions (e.g., selected tile portions) of a geometry component (e.g., instead of streaming all point cloud data) based on bandwidth availability, for example. The tile bitstreams of a point cloud component may be available in different adaptation sets, eg, an adaptation set (eg, each adaptation set) may represent a tile of the point cloud component.

[0004] Geometry-based point cloud compression (G-PCC) components may be signaled in dynamic streaming over HTTP (DASH). For example, G-PCC components may be signaled using a DASH manifest file or an MPD file. In an embodiment, G-PCC components (e.g., each G-PCC component) may be represented as an adaptation set (e.g., a separate adaptation set) in a DASH MPD file. An adaptation set (e.g., a main adaptation set) may serve as a main access point for G-PCC content. In an embodiment, an adaptation set (e.g., one adaptation set) may be signaled per component per resolution.

[0005] The G-PCC component descriptor may be signaled, for example, to enable a streaming client to identify the adaptation set and / or type of point cloud component in the representation. The G-PCC descriptor may enable a streaming client to distinguish between different point cloud streams present in an MPD file. The streaming client may identify the component streams for each point cloud stream.

[0006] G-PCC preselection may be signaled (e.g., in the MPD) with an identifier (ID) list that includes, for example, the ID of the main adaptation set of the volumetric media and the IDs of the adaptation sets that correspond to the G-PCC components. Preselection may be signaled, for example, using a preselection element within a Period element and / or using a preselection descriptor at the adaptation set level.

[0007] Multiple versions of G-PCC media may be signaled. Multiple versions of the same point cloud media may be signaled, for example, using separate pre-selections. A pre-selection representing an alternative version of the same geometry-based point cloud media may include, for example, G-PCC descriptors with the same attribute values.

[0008] One or more G-PCC tiles may be signaled. Tile bounding box information may be signaled, for example, if multiple tiles are present in the geometry-based point cloud. A client may select a tile ID from tile inventory bounding box information (e.g., in the MPD) to stream tiled G-PCC component data, for example.

[0009] A client may identify the tile ID of a point cloud component in an adaptation set, for example, by checking the G-PCC component descriptor. A G-PCC tile ID descriptor may be signaled, for example, to enable a streaming client to distinguish between G-PCC tile streams.

[0010] The characteristics of spatial regions, and / or the mapping between these regions and G-PCC tiles, may be signaled, for example, if the 3D spatial regions in geometry-based volumetric media content are static. The characteristics of spatial regions, and / or the mapping between these regions and the corresponding adaptation sets of G-PCC components, may be signaled (e.g., using G-PCC 3D region descriptors), for example, if the 3D spatial regions are static and / or tile inventory information is not available. The mapping between a spatial region and the corresponding adaptation set of G-PCC components may be signaled (e.g., by a G-PCC region ID descriptor or a G-PCC component descriptor).

[0011] (For example, indicating the position and / or dimensions of a 3D region on a presentation timeline) A time-domain metadata track can be signaled in an adaptation set (e.g., for a dynamic spatial region), for example, together with a representation, and can be associated with the main G-PCC adaptation set.

[0012] The streaming client behavior can be based on signaling. A DASH client can be guided, for example, by information provided in the MPD.

[0013] A system, method, and means for receiving content related to a geometry-based point cloud are disclosed. In an embodiment, a Media Presentation Description (MPD) file can be received, for example, from a content server. A set of preselection elements can be identified from the MPD file. One or more adaptation sets associated with at least one preselection element of the set of preselection elements can be identified. For example, one or more adaptation sets can be indicated by an attribute associated with one of the preselection elements.

[0014] A geometry-based Point Cloud Compression (GPCC) tile identifier associated with a viewport can be determined. For example, the GPCC tile identifier can be determined based on a first descriptor received within the MPD file. In an embodiment, the first descriptor can be a three-dimensional (3D) region descriptor. The 3D region descriptor can include a region location, one or more region dimensions, and / or a set of tiles associated with the 3D region.

[0015] One or more adaptation sets associated with the GPCC tile identifiers may be selected using a second descriptor. In an embodiment, the second descriptor may be a component descriptor. The component descriptor may include a component type, an attribute type, an index, and / or a set of tiles associated with the bitstream. Point cloud components associated with the selected one or more adaptation sets may be requested. In an embodiment, the point cloud components may be received.

[0016] Each feature disclosed anywhere in this specification is described and can be implemented separately / individually, as well as in combination with any other feature disclosed herein and / or with any feature disclosed elsewhere that may be implicitly or explicitly referenced herein or that may otherwise fall within the scope of the subject matter disclosed herein. [Brief explanation of the drawings]

[0017] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1C] 1A is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1D] 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 2] FIG. 1 illustrates an exemplary video encoder. [Figure 3]A diagram showing an example of a video decoder. [Figure 4] A diagram showing an example of a system in which various aspects and examples can be implemented. [Figure 5] An example of a bitstream structure for geometry-based point cloud compression (G-PCC) is shown. [Figure 6] An example of a sample structure when G-PCC geometry and attribute bitstreams are stored in a single track is shown. [Figure 7] An example of a multi-track G-PCC container is shown. [Figure 8] An exemplary media presentation description (MPD) hierarchical data model is shown. [Figure 9] An example of using preselection to group G-PCC components in an MPD is shown. [Figure 10] An example of using preselection to group multiple versions of G-PCC components in an MPD is shown. [Figure 11] An example of G-PCC content having multiple tile tracks is shown.

Mode for Carrying Out the Invention

[0018] Here, a detailed description of exemplary embodiments will be given with reference to various figures. It should be noted that this description provides detailed examples of possible implementation forms, but the details are intended to be illustrative and in no way limit the scope of this application.

[0019] FIG. 1A is a diagram showing an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 can be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to a plurality of wireless users. The communication system 100 can enable a plurality of wireless users to access the content as described above through sharing of system resources including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC).

[0020] As shown in Figure 1A, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RANs 104 / 113, CNs 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, but it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d can be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to interchangeably as a "station" and / or "STA", can be configured to transmit and / or receive wireless signals and can be a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscriber-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and application (e.g., a remote surgery), an industrial device and application (e.g., a robot and / or other wireless devices operating in an industrial and / or automated processing chain context), a home appliance device, a device operating in a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d can be referred to interchangeably as a UE.

[0021] The communication system 100 may also include base station 114a and / or base station 114b. Each of base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as CN106 / 115, Internet 110, and / or other network 112. By way of example, base stations 114a, 114b may be a base transceiver station (BTS), Node B, eNodeB, home Node B, home eNodeB, gNB, NR NodeB, site controller, access point (AP), wireless router, etc. Although base stations 114a, 114b are each shown as a single element, it will be understood that base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0022] Base station 114a may be part of RAN 104 / 113 and may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals at one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. The cell may provide wireless service coverage to a specific geographic area that may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may use multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0023] Base stations 114a, 114b may communicate with one or more of WTRUs 102a, 102b, 102c, 102d via air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Air interface 116 may be established using any suitable radio access technology (RAT).

[0024] More specifically, as described above, the communication system 100 can be a multiple access system and can use one or more channel access schemes such as, for example, CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a within RAN 104 / 113, and the WTRUs 102a, 102b, 102c can implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can establish the air interfaces 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA can include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High-Speed Downlink Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0025] In one embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0026] In one embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement radio technologies such as NR radio access, which can establish the air interface 116 using New Radio (NR).

[0027] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE radio access and NR radio access, e.g., using dual connectivity (DC) principles. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0028] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0029] The base station 114b in FIG. 1A can be, for example, a wireless router, a home Node B, a home eNode B, or an access point, and can utilize any suitable RAT to facilitate wireless connection in a local area such as an office, a home, a vehicle, a campus, an industrial facility, an aerial corridor (for example, for use by a drone), a location such as a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d can implement a wireless technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d can implement a wireless technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d can utilize a cellular-based RAT (such as WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a pico cell or a femto cell. As shown in FIG. 1A, the base station 114b can have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0030] RAN 104 / 113 can communicate with CN 106 / 115, which can be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of WTRUs 102a, 102b, 102c, 102d. The data can have various quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. CN 106 / 115 can provide call control, billing services, mobile location-based services, prepaid calls, internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in Figure 1A, it will be understood that RAN 104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs that employ the same or a different radio access technology (RAT) as RAN 104 / 113. For example, in addition to being connected to RAN 104 / 113 that can utilize New Radio (NR) radio technology, CN 106 / 115 can also communicate with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0031] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a public switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0032] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links.) For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may use a cellular-based wireless technology and a base station 114b that may use an IEEE 802 wireless technology.

[0033] Figure 1B is a system diagram showing an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power supply 134, a global positioning system (GPS) chipset 136, and / or other peripheral devices 138. It will be understood that the WTRU 102 may include any partial combination of the foregoing elements while remaining consistent with one embodiment.

[0034] The processor 118 can be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 can perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to the transceiver 120, which can be coupled to the transmit / receive element 122. Although Figure 1B shows the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 can be integrated together in an electronic package or chip.

[0035] The transmit / receive element 122 may be configured to transmit signals to a base station (e.g., base station 114a) via the air interface 116 or receive signals from a base station (e.g., base station 114a). For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0036] The transmit / receive element 122 is shown in FIG. 1B as a single element, but the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may utilize MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0037] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multimode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs such as, for example, NR and IEEE 802.11.

[0038] The processor 118 of the WTRU 102 can be coupled to the speaker / microphone 124, keypad 126, and / or display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit), and can receive data input by the user from these. The processor 118 can also output user data to the speaker / microphone 124, keypad 126, and / or display / touchpad 128. Further, the processor 118 can access information from any suitable type of memory, such as the non-removable memory 130 and / or the removable memory 132, and can store data in the memory. The non-removable memory 130 can include a random-access memory (RAM), read-only memory (ROM), hard disk, or any other type of memory storage device. The removable memory 132 can include a subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, etc. In other embodiments, the processor 118 can access information from a memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown), and can store data in the memory.

[0039] The processor 118 can receive power from the power supply 134, but can be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 can be any suitable device for supplying power to the WTRU 102. For example, the power supply 134 can include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0040] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0041] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripheral device 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, a direction sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0042] The WTRU 102 may include a full-duplex radio in which some or all of the transmission and reception of signals (e.g., for both UL (e.g., for transmission) and downlink (e.g., for reception)) associated with a particular subframe can be parallel and / or simultaneous. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference via hardware (e.g., a choke) or signal processing via a processor (e.g., via a separate processor (not shown) or the processor 118). In one embodiment, the WRTU 102 may include a half-duplex radio for the transmission and reception of some or all of the signals (e.g., associated with a particular subframe for either UL (e.g., for transmission) or downlink (e.g., for reception)).

[0043] Figure 1C is a system diagram illustrating RAN 104 and CN 106 according to one embodiment. As described above, the RAN 104 may communicate with the WTRUs 102a, 102b, 102c via the air interface 116 using E-UTRA radio technology. The RAN 104 may also communicate with the CN 106.

[0044] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with one embodiment. Each of the eNodeBs 160a, 160b, 160c may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a, for example, may transmit wireless signals to and / or receive wireless signals from the WTRU 102a using a plurality of antennas.

[0045] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling, etc. in the UL and / or DL. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0046] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. Although each of the foregoing elements is illustrated as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0047] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0048] The SGW 164 can be connected to each of the eNode-Bs 160a, 160b, and 160c in the RAN 104 via the S1 interface. The SGW 164 can generally route and transfer user data packets to / from the WTRUs 102a, 102b, and 102c. The SGW 164 can perform other functions, such as the function of anchoring the user plane during handover between eNode-Bs, the function of triggering paging when DL data is available to the WTRUs 102a, 102b, and 102c, and the function of managing and storing the contexts of the WTRUs 102a, 102b, and 102c.

[0049] The SGW 164 can be connected to the PGW 166, and the PGW 166 can provide the WTRUs 102a, 102b, and 102c with access to a packet switched network such as the Internet 110 to facilitate communication between the WTRUs 102a, 102b, and 102c and IP-enabled devices.

[0050] The CN 106 can facilitate communication with other networks. For example, the CN 106 can provide the WTRUs 102a, 102b, and 102c with access to a circuit switched network such as the PSTN 108 to facilitate communication between the WTRUs 102a, 102b, and 102c and conventional landline communication devices. For example, the CN 106 can include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that functions as an interface between the CN 106 and the PSTN 108. Further, the CN 106 can provide the WTRUs 102a, 102b, and 102c with access to other networks 112, and the other networks 112 can include other wired and / or wireless networks owned and / or operated by other service providers.

[0051] The WTRU is described as a wireless terminal in FIGS. 1A - 1D, but in certain representative embodiments, it is contemplated that such a terminal can use a wired communication interface (e.g., temporarily or permanently) with a communication network.

[0052] In a representative embodiment, the other network 112 can be a WLAN.

[0053] A WLAN in infrastructure basic service set (BSS) mode can have an access point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP can have access or an interface to another type of wired / wireless network that carries traffic entering and / or exiting the distribution system (DS) or BSS. Traffic destined for an STA that originates outside the BSS can reach and be delivered to the STA through the AP. Traffic originating from an STA to a destination outside the BSS can be sent to the AP and then transmitted to their respective destinations. Traffic between STAs within the BSS can be transmitted, for example, via the AP. The source STA can send the traffic to the AP, and the AP can deliver the traffic to the destination STA. Traffic between STAs within the BSS can be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic can be transmitted in a direct link setup (DLS) between the source STA and the destination STA (e.g., directly between them). In certain representative embodiments, the DLS can use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all of the STAs) can communicate directly with each other. The IBSS mode of communication can be referred to herein as the "ad hoc" communication mode.

[0054] When using the 802.11ac infrastructure operation mode or a similar operation mode, the AP may transmit beacons on a fixed channel such as the primary channel. The primary channel can be of a fixed width (e.g., a 20 MHz bandwidth) or a width dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by the STA to establish a connection with the AP. In certain representative embodiments, for example, in an 802.11 system, Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) with collision avoidance can be implemented. In the case of CSMA / CA, STAs including the AP (e.g., all STAs) can sense the primary channel. If the primary channel is sensed / detected as busy by a particular STA and / or determined to be so, the particular STA can back off. Only one STA (e.g., only one station) can transmit at any given time in a given BSS.

[0055] A High Throughput (HT) STA can use a 40 MHz wide channel for communication, and this 40 MHz wide channel can be formed, for example, through a combination of a primary 20 MHz channel and an adjacent or non - adjacent 20 MHz channel.

[0056] A Very High Throughput (VHT) STA may support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. The above-mentioned 40 MHz and / or 80 MHz wide channels may be formed by combining adjacent 20 MHz channels. A 160 MHz channel may be formed by combining eight adjacent 20 MHz channels or by combining two non-adjacent 80 MHz channels, which may be referred to as an 80+80 configuration. In the case of the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may split the data into two streams. The Inverse Fast Fourier Transform (IFFT) process and time domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels, and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed, and the combined data may be transmitted to the Medium Access Control (MAC).

[0057] The sub-1 GHz operating mode is supported by 802.11af and 802.11ah. The channel operating bandwidth and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using the non-TVWS spectrum. According to an exemplary embodiment, 802.11ah may support meter type control / machine type communication, such as MTC devices within a macro coverage area. The MTC device may have certain capabilities, including, for example, support for a specific and / or limited bandwidth (e.g., support only therefor). The MTC device may include a battery having a battery life exceeding a threshold (e.g., to maintain a very long battery life).

[0058] A WLAN system that can support multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah includes channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or restricted by an STA from among all STAs operating in a BSS that supports a minimum bandwidth operating mode. In the example of 802.11ah, the primary channel can be 1 MHz wide for an STA (e.g., an MTC type device) that supports the 1 MHz mode (e.g., supports only that) even when the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) setting can depend on the state of the primary channel. For example, if the primary channel is busy due to an STA transmitting to the AP (supporting only the 1 MHz operating mode), the entire available frequency band can be considered busy even though most of the frequency band remains idle and available.

[0059] In the United States, the available frequency band that can be used by 802.11ah is 902 MHz to 928 MHz. In Korea, the available frequency band is 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0060] FIG. 1D is a system diagram illustrating RAN 113 and CN 115 according to one embodiment. As described above, RAN 113 can communicate with WTRUs 102a, 102b, 102c via air interface 116 using NR radio technology. RAN 113 can also communicate with CN 115.

[0061] RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that RAN 113 may include any number of gNBs while maintaining consistency with one embodiment. Each of gNBs 180a, 180b, and 180c may include one or more transceivers for communicating with WTRUs 102a, 102b, and 102c via air interface 116. In one embodiment, gNBs 180a, 180b, and 180c may implement MIMO technology. For example, gNBs 180a and 108b may utilize beamforming to transmit and / or receive signals to / from gNBs 180a, 180b, and 180c. Thus, gNB 180a may, for example, transmit a wireless signal to WTRU 102a and / or receive a wireless signal from WTRU 102a using multiple antennas. In one embodiment, gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB 180a may transmit multiple component carriers to WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum and the remaining component carriers may be on licensed spectrum. In one embodiment, gNBs 180a, 180b, and 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0062] WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c using transmissions associated with an expandable numerology. For example, the OFDM symbol interval and / or the OFDM sub-carrier interval may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., including various numbers of OFDM symbols and / or having absolute times of various lengths).

[0063] gNBs 180a, 180b, and 180c may be configured to communicate with WTRUs 102a, 102b, and 102c in a stand-alone configuration and / or a non-stand-alone configuration. In a stand-alone configuration, WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c without accessing other RANs (e.g., eNodeBs 160a, 160b, and 160c, etc.). In a stand-alone configuration, WTRUs 102a, 102b, and 102c may utilize one or more of gNBs 180a, 180b, and 180c as a mobility anchor point. In a stand-alone configuration, WTRUs 102a, 102b, and 102c may communicate with gNBs 180a, 180b, and 180c using signals in an unlicensed band. In a non-stand-alone configuration, WTRUs 102a, 102b, and 102c may communicate with and connect to gNBs 180a, 180b, and 180c while also communicating with and connecting to another RAN such as eNodeBs 160a, 160b, and 160c. For example, WTRUs 102a, 102b, and 102c may implement a DC principle for communicating with one or more gNBs 180a, 180b, and 180c and one or more eNodeBs 160a, 160b, and 160c substantially simultaneously. In a non-stand-alone configuration, eNodeBs 160a, 160b, and 160c may function as a mobility anchor for WTRUs 102a, 102b, and 102c, while gNBs 180a, 180b, and 180c may provide additional coverage and / or throughput for serving WTRUs 102a, 102b, and 102c.

[0064] Each of gNBs 180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to user plane functions (UPFs) 184a, 184b, and routing of control plane information to access and mobility management functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, gNBs 180a, 180b, and 180c can communicate with each other via the Xn interface.

[0065] CN 115 shown in FIG. 1D can include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and optionally data networks (DNs) 185a, 185b. Although each of the foregoing elements is shown as part of CN 115, it will be understood that any of these elements can be owned and / or operated by entities other than the CN operator.

[0066] AMF 182a and 182b can be connected to one or more of gNBs 180a, 180b, and 180c in RAN 113 via the N2 interface and can function as control nodes. For example, AMF 182a and 182b can play roles such as user authentication of WTRUs 102a, 102b, and 102c, support for network slicing (e.g., handling different PDU sessions with different requirements), selection of specific SMFs 183a and 183b, registration area management, termination of NAS signaling, and mobility management. Network slices can be used by AMF 182a and 182b to customize the CN support for WTRUs 102a, 102b, and 102c based on the type of services being utilized by WTRUs 102a, 102b, and 102c. For example, different network slices can be established for different use cases such as services that rely on ultra-reliable low latency (URLLC) access, services that rely on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. AMF 162 can provide control plane functions for switching between RAN 113 and other RANs (not shown) that employ other radio technologies such as non-3GPP access technologies like LTE, LTE-A, LTE-A Pro, and / or WiFi.

[0067] SMF183a and 183b can be connected to AMF182a and 182b within CN115 via the N11 interface. SMF183a and 183b can also be connected to UPF184a and 184b within CN115 via the N4 interface. SMF183a and 183b can select and control UPF184a and 184b and configure the routing of traffic passing through UPF184a and 184b. SMF183a and 183b can perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. The PDU session type can be IP-based, non-IP-based, Ethernet-based, etc.

[0068] UPF184a and 184b can be connected to one or more of gNB180a, 180b, and 180c within RAN113 via the N3 interface, thereby providing access to a packet-switched network such as the Internet 110 to WTRU102a, 102b, and 102c to facilitate communication between WTRU102a, 102b, and 102c and IP-corresponding devices. UPF184 and 184b can perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-home PDU sessions, processing user plane QoS, buffering downlink packets, and providing mobility anchoring.

[0069] CN115 may facilitate communication with other networks. For example, CN115 may include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that functions as an interface between CN115 and the PSTN 108. Further, CN115 may provide access to other networks 112 for the WTRUs 102a, 102b, 102c, and the other networks 112 may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0070] Referring to FIGS. 1A - 1D and the corresponding descriptions of FIGS. 1A - 1D, one or more of the functions described herein related to one or more of the WTRUs 102a - d, base stations 114a - b, eNode - Bs 160a - c, MME 162, SGW 164, PGW 166, gNBs 180a - c, AMFs 182a - b, UPFs 184a - b, SMFs 183a - b, DNs 185a - b, and / or any other devices described herein may be implemented by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functionality.

[0071] An emulation device can be designed to implement one or more tests of other devices in a laboratory environment and / or an operator network environment. For example, one or more emulation devices can be fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network, and can execute one or more or all functions while being deployed. One or more emulation devices can execute one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. An emulation device can be directly coupled to another device for testing purposes and / or can execute tests using terrestrial wireless communication.

[0072] One or more emulation devices can execute one or more functions including all while not being implemented / deployed as part of a wired and / or wireless communication network. For example, an emulation device can be utilized in a test scenario in a test laboratory and / or in a wired and / or wireless communication network that is not deployed (e.g., for testing) to implement tests of one or more components. One or more emulation devices can be test equipment. Direct RF coupling and / or wireless communication via an RF circuit (which can include one or more antennas) can be used by an emulation device to transmit and / or receive data.

[0073] This application describes various aspects including tools, features, examples or embodiments, models, approaches, etc. Many of these aspects are specifically described and often described in a way that may sound limiting in order to show at least individual characteristics. However, this is for the purpose of clarifying the description and does not limit the application or scope of those aspects. In fact, all of the different aspects can be combined and exchanged to provide further aspects. Moreover, aspects can similarly be combined and exchanged with aspects described in prior applications.

[0074] The aspects described and contemplated in this application can be implemented in many different forms. The figures 5 to 8 described herein may provide some embodiments, but other embodiments are also contemplated. The consideration of figures 5 to 8 does not limit the scope of the implementation forms. At least one of the aspects generally relates to video encoding and decoding, and at least one other aspect generally relates to transmitting a generated or encoded bitstream. These and other aspects can be implemented as a method, an apparatus, a computer-readable storage medium storing instructions for encoding or decoding video data according to any of the described methods, and / or a computer-readable storage medium storing a bitstream generated according to any of the described methods.

[0075] In this application, the terms "reconstructed" and "decoded" may be used interchangeably, the terms "pixel" and "sample" may be used interchangeably, and the terms "image", "picture", and "frame" may be used interchangeably.

[0076] Various methods are described herein, and each of the methods includes one or more steps or actions for achieving the described method. Unless a particular order of steps or actions is required for proper operation of the method, the order and / or use of particular steps and / or actions may be modified or combined. Additionally, terms such as "first," "second," etc. may be used in various embodiments to modify elements, components, steps, actions, etc., such as "first decoding" and "second decoding." The use of such terms does not imply an ordering with respect to the modified operations, unless specifically required. Thus, in this example, the first decoding need not be performed before the second decoding and may occur, for example, before, during, or overlapping with the second decoding.

[0077] The various methods and other aspects described in this application may modify (e.g., be used to modify) modules of the video encoder 200 and video decoder 300 as shown in FIGS. 2 and 3, respectively, such as pre-encoding processing 201, intra prediction 260, entropy coding 245, and / or entropy decoding module 330, intra prediction 360, post-decoding processing 385. Further, the subject matter disclosed herein presents aspects that are not limited to VVC or HEVC and may be applied to any type, format, or version of video coding, as well as extensions of any such standards and recommendations (including, e.g., VVC and HEVC), whether existing or to be developed in the future, regardless of whether described in a standard or recommendation. Unless otherwise indicated or technically excluded, the aspects described in this application may be used individually or in combination.

[0078] Various numerical values such as a minimum value range and a maximum value range (e.g., 0 to 1, 0 to N, or 0 to 255), bit values for indication or determination, default values, ID numbers (e.g., for adaptation IDs), etc. are used in the embodiments described in this application. These and other specific values are for the purpose of describing the embodiments, and the described aspects are not limited to these specific values.

[0079] FIG. 2 is a diagram showing an exemplary video encoder. Although variations of the exemplary encoder 200 are contemplated, the encoder 200 is described below for clarity purposes without explaining all the expected variations.

[0080] Before being encoded, the video sequence undergoes pre-encoding processing (201), for example, applying a color conversion to the input color picture (e.g., conversion from RGB4:4:4 to YCbCr4:2:0), or performing remapping of the input picture components to obtain a more flexible signal distribution for compression (e.g., using histogram equalization of one of the color components). Metadata is associated with that pre-processing and can be attached to the bitstream.

[0081] In encoder 200, as described below, pictures are encoded by encoder elements. The picture to be encoded is divided (202) and processed, for example, in units of coding units (CUs). Each unit is encoded using either an intra mode or an inter mode. When a unit is encoded in the intra mode, that unit performs intra prediction (260). In the inter mode, motion estimation (275) and motion compensation (270) are performed. The encoder determines (205) which of the intra mode or the inter mode should be used to encode the unit, for example, indicating the intra / inter determination by a prediction mode flag. The prediction residual is calculated, for example, by subtracting the block predicted from the original image block (210).

[0082] The prediction residual is then transformed (225) and quantized (230). The quantized transform coefficients, along with motion vectors and other syntax elements, are entropy encoded (245) to output a bitstream. The encoder can skip the transformation and apply quantization directly to the untransformed residual signal. The encoder can bypass both the transformation and quantization, i.e., the residual is directly encoded without applying the transformation process or the quantization process.

[0083] The encoder decodes the encoded block to provide a reference for further prediction. The quantized transform coefficients are inverse quantized (240) and inverse transformed (250) to decode the prediction residual. The decoded prediction residual and the predicted block are combined (255) to reconstruct the image block. A loop filter (265) is applied to the reconstructed picture, for example, to perform deblocking / SAO (Sample Adaptive Offset) filtering to reduce coding artifacts. The filtered image is stored in a reference picture buffer (280).

[0084] FIG. 3 is a diagram illustrating an example of a video decoder. In an exemplary decoder 300, the bitstream is decoded by decoder elements as described below. The video decoder 300 generally performs a decoding path that is inverse to the encoding path as described in FIG. 2. The encoder 200 may also generally perform video decoding as part of encoding video data. For example, the encoder 200 may perform one or more of the video decoding steps presented herein. The encoder reconstructs the decoded image and maintains synchronization with the decoder with respect to, for example, one or more of a reference picture, an entropy coding context, and other decoder-related state variables.

[0085] In particular, the input to the decoder may include a video bitstream and may be generated by the video encoder 200. The bitstream is first entropy decoded (330) to obtain transform coefficients, motion vectors, and other coding information. The picture partitioning information indicates how the picture is partitioned. The decoder can thus partition the picture according to the decoded picture partitioning information (335). The transform coefficients are inverse quantized (340) and inverse transformed (350) to decode the prediction residuals. The decoded prediction residuals are combined with the predicted blocks (355) to reconstruct the image blocks. The predicted blocks can be obtained from intra prediction (360) or motion compensated prediction (i.e., inter prediction) (375) (370). The in-loop filter (365) is applied to the reconstructed image. The filtered image is stored in the reference picture buffer (380).

[0086] The decoded picture may further undergo post-decoding processing (385), such as inverse color conversion (e.g., conversion from YCbCr 4:2:0 to RGB 4:4:4), or inverse remapping that performs the inverse of the remapping process performed in the pre-encoding processing (201). The post-decoding processing can use metadata derived in the pre-encoding processing and signaled in the bitstream.

[0087] FIG. 4 is a diagram illustrating an example of a system in which various aspects and embodiments described herein may be implemented. System 400 may be embodied as a device that includes various components described below and is configured to execute one or more of the aspects described herein. Examples of such devices include, but are not limited to, various electronic devices such as personal computers, laptop computers, smartphones, tablet computers, digital multimedia set-top boxes, digital television receivers, personal video recording systems, connected home appliances, and servers. The elements of System 400 may be embodied, alone or in combination, in a single integrated circuit (IC), multiple ICs, and / or discrete components. For example, in at least one embodiment, the processing and encoder / decoder elements of System 400 are distributed across multiple ICs and / or discrete components. In various embodiments, System 400 is communicatively coupled to one or more other systems or other electronic devices, for example, via a communication bus or through dedicated input ports and / or output ports. In various embodiments, System 400 is configured to implement one or more of the aspects described herein.

[0088] System 400 includes at least one processor 410 configured to execute instructions loaded therein, for example, to implement various aspects described herein. Processor 410 can include embedded memory, input / output interfaces, and various other circuits known in the art. System 400 includes at least one memory 420 (e.g., volatile memory devices and / or non-volatile memory devices). System 400 includes a storage device 440, which can include non-volatile memory and / or volatile memory, such as electrically erasable programmable read-only memory (EEPROM), read-only memory (ROM), programmable read-only memory (PROM), random access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash, magnetic disk drive, and / or optical disk drive, but is not limited thereto. Storage device 440 can include, by way of non-limiting example, an internal storage device, an attached storage device (including removable and non-removable storage devices), and / or a network-accessible storage device.

[0089] System 400 includes, for example, an encoder / decoder module 430 configured to process data to provide encoded video or decoded video, and the encoder / decoder module 430 can include its own processor and memory. The encoder / decoder module 430 represents a module that can be included within a device to perform an encoding function and / or a decoding function. As is known, a device can include one or both of an encoding module and a decoding module. Additionally, the encoder / decoder module 430 can be implemented as an individual element of the system 400 or can be incorporated within the processor 410 as a combination of hardware and software, as is known to those skilled in the art.

[0090] The program code loaded onto the processor 410 or the encoder / decoder 430 to execute the various aspects described herein can be stored in the storage device 440 and then loaded onto the memory 420 for execution by the processor 410. According to various embodiments, one or more of the processor 410, the memory 420, the storage device 440, and the encoder / decoder module 430 can store one or more of the various items during the execution of the storage process described herein. Such stored items can include, but are not limited to, input video, decoded video, or a portion of the decoded video, bitstream, matrix, variable, and intermediate or final results from the processing of equations, expressions, operations, and operation logics.

[0091] In some embodiments, the memory internal to the processor 410 and / or the encoder / decoder module 430 is used to store instructions and provide a working memory for the processing required during encoding or decoding. However, in other embodiments, a memory external to the processing device (e.g., the processing device can be either the processor 410 or the encoder / decoder module 430) is used for one or more of these functions. The external memory can be the memory 420 and / or the storage device 440, e.g., dynamic volatile memory and / or non-volatile flash memory. In some embodiments, an external non-volatile flash memory is used to store, for example, the operating system of a television. In at least one embodiment, a high-speed external dynamic volatile memory such as RAM is used as a working memory for video encoding and decoding operations such as MPEG-2 (MPEG refers to Moving Picture Experts Group, MPEG-2 is also referred to as ISO / IEC 13818, 13818-1 is also known as H.222, and 13818-2 is also known as H.262), HEVC (HEVC, High Efficiency Video Coding refers to high-efficiency video coding and is also known as H.265 and MPEG-H Part 2), or VVC (Versatile Video Coding is a new standard being developed by the JVET, Joint Video Experts Team).

[0092] Inputs to the elements of system 400 can be provided through various input devices, as shown in block 445. Such input devices include, but are not limited to, (i) a radio frequency (RF) section that receives, for example, an RF signal transmitted over the airwaves by a broadcast station, (ii) a component (COMP) input terminal (or a set of COMP input terminals), (iii) a universal serial bus (USB) input terminal, and / or (iv) a high definition multimedia interface (HDMI) input terminal. Other examples include composite video, although not shown in FIG. 4.

[0093] In various embodiments, the input device of block 445 has respective input processing elements known in the art. For example, the RF portion can be associated with elements suitable for (i) selecting a desired frequency (also referred to as selecting a signal or band-limiting a signal to a frequency in a band), (ii) down-converting the selected signal, (iii) again band-limiting to a narrower frequency band to select a signal frequency band that may be referred to as a channel in certain embodiments, (iv) demodulating the down-converted and band-limited signal, (v) performing error correction, and (vi) demultiplexing to select a desired data packet stream. The RF portion of various embodiments can include one or more elements for performing these functions, such as a frequency selector, signal selector, band limiter, channel selector, filter, down-converter, demodulator, error corrector, and demultiplexer. The RF portion can include a tuner for performing various of these functions, including, for example, down-converting a received signal to a lower frequency (e.g., an intermediate frequency or near baseband frequency) or to baseband. In one embodiment of a set-top box, the RF portion and its associated input processing elements receive an RF signal transmitted via a wired (e.g., cable) medium and perform frequency selection by filtering, down-converting, and re-filtering to a desired frequency band. In various embodiments, the order of the elements described above (and others) can be rearranged, some of these elements can be deleted, and / or other elements performing similar or different functions can be added. Adding elements can include, for example, inserting elements between existing elements, such as inserting an amplifier and an analog-to-digital converter. In various embodiments, the RF portion includes an antenna.

[0094] In addition, the USB terminal and / or the HDMI terminal can each include an interface processor for connecting the system 400 to other electronic devices via a USB connection and / or an HDMI connection. It should be understood that various aspects of input processing, such as Reed-Solomon error correction, can be implemented, for example, within an individual input processing IC or within the processor 410 as needed. Similarly, aspects of USB or HDMI interface processing can be implemented, as needed, within an individual interface IC or within the processor 410. The demodulated, error-corrected, and multiplexed-separated streams are provided to various processing elements, including, for example, the processor 410 and an encoder / decoder 430 that operates in combination with memory and storage elements to process the data stream as needed for presentation on the output device.

[0095] The various elements of the system 400 can be provided within an integrated housing. Within the integrated housing, the various elements can be interconnected and data can be transmitted between those elements using an internal bus, such as a suitable connection configuration 425, including, for example, an Inter-IC (I2C) bus, wiring, and a printed circuit board, as known in the art.

[0096] The system 400 includes a communication interface 450 that enables communication with other devices via a communication channel 460. The communication interface 450 can include, but is not limited to, a transceiver configured to transmit and receive data via the communication channel 460. The communication interface 450 can include, but is not limited to, a modem or a network card, and the communication channel 460 can be implemented, for example, within a wired and / or wireless medium.

[0097] In various embodiments, data is streamed to or otherwise provided to system 400 using a Wi-Fi network, such as a wireless network like IEEE 802.11 (IEEE, the Institute of Electrical and Electronics Engineers, refers to the Institute of Electrical and Electronics Engineers in the United States). The Wi-Fi signals of these examples are received via a communication channel 460 and a communication interface 450 adapted for Wi-Fi communication. The communication channel 460 of these embodiments is typically connected to an access point or router that provides access to an external network, including the Internet, to enable streaming applications and other over-the-top communications. In other embodiments, a set-top box that distributes data via the HDMI connection of input block 445 is used to provide streaming data to system 400. In still other embodiments, the RF connection of input block 445 is used to provide streaming data to system 400. As shown above, various embodiments provide data in a non-streaming manner. Additionally, various embodiments use wireless networks other than Wi-Fi, such as cellular networks or Bluetooth networks.

[0098] System 400 can provide output signals to various output devices including display 475, speaker 485, and other peripheral devices 495. The display 475 of various embodiments includes, for example, one or more of a touch screen display, an organic light emitting diode (OLED) display, a curved display, and / or a foldable display. The display 475 can be for a television, a tablet, a laptop, a mobile phone, or other device. The display 475 can also be integrated with other components (such as in a smartphone) or separate (such as an external monitor for a laptop). As other peripheral devices 495, in various examples of embodiments, one or more of a stand-alone digital video disc (or digital versatile disc) (for both terms, DVR, digital versatile disc), a disc player, a stereo system, and / or a lighting system are included. Various embodiments use one or more peripheral devices 495 that provide functions based on the output of system 400. For example, a disc player performs the function of playing back the output of system 400.

[0099] In various embodiments, the control signal is communicated between the system 400 and the display 475, the speaker 485, or other peripheral device 495 using signaling such as AV.Link, Consumer Electronics Control (CEC), or other communication protocols that enable control between devices regardless of the presence or absence of user intervention. The output devices can be communicatively coupled to the system 400 via dedicated connections through their respective interfaces 470, 480, and 490. Alternatively, the output devices can be connected to the system 400 using the communication channel 460 via the communication interface 450. The display 475 and the speaker 485 can be integrated into a single unit with other components of the system 400, such as within an electronic device, e.g., a television. In various embodiments, the display interface 470 includes a display driver, such as a timing controller (T Con) chip, for example.

[0100] Alternatively, the display 475 and the speaker 485 can be separated from one or more of the other components, for example, if the RF portion of the input 445 is part of a separate set-top box. In various embodiments where the display 475 and the speaker 485 are external components, the output signal can be provided via a dedicated output connection, including, for example, an HDMI port, a USB port, or a COMP output.

[0101] The embodiments can be implemented by computer software executed by a processor 410, or by hardware, or by a combination of hardware and software. As a non-limiting example, the embodiments can be implemented by one or more integrated circuits. The memory 420 can be of any type suitable for the technical environment and can be implemented using any suitable data storage technology, such as, by way of non-limiting example, optical memory devices, magnetic memory devices, semiconductor-based memory devices, fixed memory, and removable memory. The processor 410 can be of any type suitable for the technical environment and can include, by way of non-limiting example, one or more of a microprocessor, a general-purpose computer, a dedicated computer, and a processor based on a multi-core architecture.

[0102] Various implementations include decoding. As used in this application, "decoding" may include all or part of a process performed on a received encoded sequence, for example, to generate a final output suitable for display. In various embodiments, such a process may include, for example, one or more of the processes typically performed by a decoder, such as entropy decoding, inverse quantization, inverse transform, and differential decoding. In various embodiments, such a process may also or alternatively include the processes performed by the decoders of the various implementations described in this application, for example, receiving, decoding, and interpreting signals (such as those described herein) indicating elements, attributes, and metadata associated with point cloud components, identifying point cloud streams and their component sub-streams within a media presentation descriptor (MPD), identifying the version of a point cloud and / or components of a point cloud, decoding the MPD to identify a main adaptation set and other adaptation sets and to identify G-PCC components in geometry-based point cloud compression (G-PCC) content, decoding the MPD to identify the type of point cloud components in an adaptation set or representation, decoding the MPD to identify one or more pre-selections, decoding the MPD to identify one or more versions of G-PCC media, decoding the MPD to identify one or more G-PCC tile groups, decoding the MPD to identify one or more tile IDs of G-PCC components in an adaptation set, decoding the MPD to identify one or more characteristics of spatial regions and the mapping between these regions and G-PCC tiles, the characteristics of spatial regions and the mapping between these regions and the corresponding adaptation sets of G-PCC components, and / or the mapping between spatial regions and the corresponding adaptation sets of G-PCC components, decoding the MPD to identify the time domain metadata track of a dynamic spatial region, and so on.

[0103] As a further embodiment, in one example, decoding may refer to entropy decoding, in another embodiment, decoding may refer to differential decoding, and in another embodiment, decoding may refer to a combination of entropy decoding and differential decoding. Whether the phrase decoding process is intended to specifically refer to a subset of operations or generally to a broader decoding process will become apparent based on the specific context of the description and is considered to be well understood by those skilled in the art.

[0104] Various implementations may involve encoding. Similar to the above considerations regarding decoding, the encoding used in this application may include all or part of a process that is performed on an input video sequence, for example, to generate an encoded bitstream. In various embodiments, such a process may include one or more of the processes typically performed by an encoder, such as, for example, splitting, differential encoding, transformation, quantization, and entropy encoding. In various embodiments, such a process may also or alternatively include the processes performed by the encoders of the various implementations described in this application, for example, generating, encoding, and transmitting signals that indicate elements, attributes, and metadata associated with point cloud components (e.g., as described herein), encoding the MPD to indicate point cloud streams and component sub-streams of these point cloud streams, encoding the MPD to support the identification of geometry-based point cloud compression (G-PCC) components in G-PCC content by indicating main adaptation sets and other adaptation sets, encoding the MPD to support the identification of the type of point cloud component in an adaptation set or representation, encoding the MPD to identify one or more pre-selections, encoding the MPD to support the identification of one or more versions of G-PCC media, encoding the MPD to support the identification of one or more G-PCC tile groups, encoding the MPD to support the identification of one or more tile IDs of G-PCC components in an adaptation set, encoding the MPD to support the identification of one or more characteristics of a spatial region and the mapping between these regions and G-PCC tiles, the characteristics of the spatial region and the mapping between these regions and the corresponding adaptation sets of G-PCC components, and / or the mapping between the spatial region and the corresponding adaptation sets of G-PCC components, decoding the MPD to identify the time-domain metadata track of a dynamic spatial region, and so on.

[0105] As a further example, in one embodiment, encoding may refer to entropy encoding, in another embodiment, encoding may refer to differential encoding, and in another embodiment, encoding may refer to a combination of differential encoding and entropy encoding. Whether the phrase "encoding process" is intended to specifically refer to a subset of operations or generally to a broader encoding process will become apparent based on the specific context of the description and is considered to be well understood by those skilled in the art.

[0106] Note that the syntactic elements used herein, such as those shown in Tables 1 to 23 and which may be otherwise shown in the considerations or figures presented herein, are descriptive terms. Thus, these do not preclude the use of other syntactic element names.

[0107] When a figure is presented as a flowchart, it should be understood that the figure also provides a block diagram of the corresponding apparatus. Similarly, when a figure is presented as a block diagram, it should be understood that the figure also provides a flowchart of the corresponding method / process.

[0108] During the symbolic processing, usually, often due to the constraints of computational complexity, a balance or trade-off between the rate and distortion is considered. Rate-distortion optimization is typically formulated to minimize the rate-distortion function, which is a weighted sum of the rate and distortion. To solve the rate-distortion optimization problem, there are different approaches. For example, these approaches can be based on an extensive test of all coding options including all considered modes or coding parameter values, involving a complete evaluation of their coding costs and the associated distortion of the reconstructed signals after coding and decoding. To reduce the coding complexity, faster approaches can be used, especially those that use an approximate distortion calculation based on the predicted or prediction residual signal rather than the reconstructed signal. A mixture of these two approaches can be used, for example, by using the approximate distortion of some of the possible coding options and the complete distortion of other coding options. In other approaches, a subset of the possible coding options can be evaluated. More generally, many approaches employ any of various techniques to perform the optimization, but the optimization does not necessarily involve a complete evaluation of both the coding cost and the associated distortion.

[0109] The implementations and aspects described herein can be implemented, for example, in a method or process, a device, a software program, a data stream, or a signal. Even if considered only in the context of a single form of implementation (e.g., only considered as a method), the implementation of the considered features can also be implemented in other forms (e.g., a device or a program). The device can be implemented, for example, with appropriate hardware, software, and firmware. The method can be implemented, for example, by a processor, where the processor generally refers to a processing device and includes, for example, a computer, a microprocessor, an integrated circuit, or a programmable logic device. The processor can also include a communication device such as a computer, a mobile phone, a portable / personal digital assistant (PDA), and other devices that facilitate the communication of information between the end user.

[0110] References to "one embodiment", "an embodiment", "an example", "one implementation", or "an implementation", and other variations thereof, mean that the specific features, structures, characteristics, etc. described in connection with the embodiment are included in at least one embodiment. Thus, the phrases "in one embodiment", "in an example", "in one implementation", or "in an implementation", and the appearance of any other variations thereof, which appear in various places throughout this specification, do not necessarily all refer to the same embodiment or example.

[0111] In addition, this application may refer to "determining" various information. Determining information can include, for example, one or more of estimating information, calculating information, predicting information, or retrieving information from memory. Obtaining can include receiving, retrieving, constructing, generating, and / or determining.

[0112] Furthermore, this application may refer to "accessing" various information. Accessing information can include, for example, one or more of receiving information, obtaining information (e.g., from memory), storing information, moving information, copying information, calculating information, determining information, predicting information, or estimating information.

[0113] In addition, this application may refer to "receiving" various information. Receiving is intended to be a broad term, similar to "accessing". Receiving information can include, for example, accessing the information or obtaining the information (e.g., from a memory), among one or more of these. Further, "receiving" generally involves, in some form, during operations such as storing information, processing information, transmitting information, moving information, copying information, deleting information, calculating information, determining information, predicting information, or estimating information.

[0114] For example, in the case of "A / B", "A and / or B", and "at least one of A and B", it should be understood that any use of the following " / ", "and / or", and "at least one of" is intended to include the selection of only the first-listed option (A), or only the second-listed option (B), or the selection of both options (A and B). As a further example, in the case of "A, B, and / or C" and "at least one of A, B, and C", such expressions include the selection of only the first-listed option (A), or only the second-listed option (B), or only the third-listed option (C), or the selection of only the first and second-listed options (A and B), or the selection of only the first and third-listed options (A and C), or the selection of only the second and third-listed options (B and C), or the selection of all three options (A and B and C). As will be apparent to those of ordinary skill in the art in the relevant art and related arts, this can be extended for the number of listed items.

[0115] Also, as used herein, the term "signaling" means, among other things, indicating something to the corresponding decoder. For example, in some embodiments, the encoder signals, e.g., to the decoder, MPD, adaptation sets, representations, pre-selections, G-PCC components, G-PCC Component descriptors, G-PCC descriptors or Essential Property descriptors, Supplementary Property descriptors, G-PCC Tile Inventory descriptors, G-PCC Static Spatial Region descriptors, GPCCTileId descriptors, GPCC3DRegionID descriptors, among others, such as descriptors, elements and attributes, metadata, schemas (including, e.g., Tables 1 to 23 disclosed herein). In this way, in one embodiment, the same parameters can be used on both the encoder side and the decoder side. Thus, for example, the encoder can send (explicitly signal) specific parameters to the decoder so that the decoder can use the same specific parameters. Conversely, if the decoder already has specific parameters as well as other parameters, signaling can be used (implicit signaling) without sending, simply enabling the decoder to know and select the specific parameters. By avoiding the transmission of any actual functionality, bit savings are achieved in various embodiments. It should be understood that signaling can be achieved in various ways. For example, one or more syntax elements, flags, etc. are used in various embodiments to signal information to the corresponding decoder. The foregoing relates to the verb form of the word "signaling", but the word "signal" can also be used as a noun herein.

[0116] As will be apparent to those skilled in the art, the implementation form can generate various signals formatted to carry information that can be stored or transmitted, for example. The information can include, for example, instructions for executing a method or data generated by one of the described implementation forms. For example, the signal can be formatted to carry a bitstream of the described embodiment. Such a signal can be formatted, for example, as an electromagnetic wave (e.g., using the radio frequency portion of the spectrum) or as a baseband signal. Formatting can include, for example, encoding a data stream and modulating a carrier wave with the encoded data stream. The signal carried by the signal can be, for example, analog information or digital information. As is known, the signal can be transmitted by various different wired or wireless links. The signal can be stored in a processor-readable medium.

[0117] A 3D point cloud may represent (e.g., be used to represent) an immersive media. The point cloud may include a set of points represented in a three-dimensional (3D) space. In an example, a point (e.g., each point) may be associated with one or more coordinates indicating the location of the point and / or one or more attributes (e.g., point color, transparency, acquisition time, laser reflectance, material properties, etc.). The point cloud may be captured or developed using, for example, one or more cameras, depth sensors, and / or light detection and ranging (LiDAR) laser scanners. The point cloud may include a plurality of points. In an example, a point (e.g., each point) may be represented by a set of coordinates (e.g., x, y, z coordinates) that map in 3D space. The points may be generated based on sampling of an object. In an example, the number of points in the point cloud may be on the order of millions or billions. The point cloud may be used to reconstruct one or more objects and / or scenes. The point cloud may be represented and / or compressed, for example, to store and / or transmit (e.g., efficiently store and / or transmit) point cloud data. Point cloud compression may support irreversible coding and / or reversible coding (e.g., encoding or decoding) of geometric coordinates and / or attributes of the point cloud. The point cloud may be developed to support various applications (e.g., telepresence, virtual reality (VR), and / or large-scale dynamic 3D mapping). In an example, libraries for mesh and point cloud compression may support compression of vertex positions, normals, colors, texture coordinates, and other general vertex attributes, for example, to improve the efficiency and speed of transmitting 3D content. An example of such a library is DRACO (TM) developed by GOOGLE (TM).

[0118] FIG. 5 shows an example of a bitstream structure for geometry-based point cloud compression (G-PCC). The G-PCC bitstream may include a set of G-PCC units, which may be referred to as, for example, a type-length-value (TLV) encapsulation structure as shown in FIG. 5. G-PCC and GPCC may be used interchangeably herein. As shown in FIG. 5, the G-PCC unit may include information regarding the G-PCC tlv_type and the G-PCC tlv unit payload. FIG. 5 shows various tlv unit payload types. Table 1 shows an example of the G-PCC TLV syntax. In the example, the G-PCC TLV unit (e.g., each G-PCC TLV unit) may include a TLV type, a G-PCC TLV unit payload length, and / or a G-PCC TLV unit payload. The TLV type (e.g., the tlv_type shown in Table 1) may indicate the G-PCC unit type. Table 2 shows an example of the TLV type (e.g., the tlv_type shown in Table 1) and the associated data unit description. For example, the G-PCC TLV unit of unit type 2 may be a geometry data unit, and the G-PCC TLV unit of unit type 4 may be an attribute data unit. The point cloud may be reconstructed based on, for example, the geometry data unit and the attribute data unit. The geometry and / or attribute G-PCC unit payload may correspond to a media data unit (e.g., a TLV unit) that may be decoded by, for example, a G-PCC decoder. The geometry and attribute parameter set G-PCC units may specify a G-PCC decoder for decoding the corresponding TLV units. The G-PCC bitstream high-level syntax (HLS) may support slices and / or tile groups for geometry and attribute data. The frame may be divided into a plurality of tiles and slices. A slice may be a set of points that may be encoded or decoded (e.g., independently encoded or decoded). In the example, a slice may include a geometry data unit and zero or more attribute data units.An attribute data unit may depend on, for example, a corresponding geometry data unit within the same slice. Within a slice, the geometry data unit may appear before any associated attribute units. The data units of a slice may be contiguous. The ordering of slices within a frame may not be specified. A group of slices may be identified by a common tile identifier. A tile inventory may be implemented that describes the bounding box of a tile (e.g., each tile). Tiles may overlap with another tile within the bounding box. Each slice may include an index that identifies to which tile the slice belongs. Table 1 shows an example of the G-PCC TLV encapsulation unit payload syntax, Table 2 shows an example of the G-PCC TLV type and data unit description, and Table 3 shows an example of the G-PCC TLV encapsulation unit payload syntax.

[0119]

Table 1

[0120]

Table 2

[0121]

Table 3

[0122] The G-PCC container file format may be implemented. FIG. 6 shows an example of a sample structure when the G-PCC geometry and attribute bitstreams can be stored in a single track. A video coding device may require, for example, that when the G-PCC bitstream is conveyed in a single track, the G-PCC encoded bitstream is represented by a single track declaration. The single-track encapsulation of G-PCC data may utilize a simple encapsulation, such as ISO base media file format (ISOBMFF) encapsulation, by, for example, storing the G-PCC bitstream in a single track without processing (e.g., further processing). Each sample in a single track (e.g., each sample) (e.g., each sample in the track) may include one or more G-PCC components. Each sample may include one or more TLV encapsulation structures.

[0123] FIG. 7 shows an example of a multi-track (e.g., ISOBMFF) G-PCC container structure. The encoded G-PCC geometry bitstream and the encoded G-PCC attribute bitstream are stored in separate tracks, and each sample in the track may include at least one TLV encapsulation structure that conveys G-PCC component data.

[0124] A multi-track G-PCC ISOBMFF container may contain G-PCC tracks containing Geometry parameter sets, Sequence parameter sets, and / or geometry bitstream samples carrying geometry data TLV units. A G-PCC track may contain track references to other tracks carrying G-PCC attribute component payloads. A multi-track G-PCC ISOBMFF container may contain zero or more G-PCC tracks, each containing a respective attribute attribute parameter set and attribute bitstream samples carrying attribute data TLV units.

[0125] When a G-PCC bitstream is carried on multiple tracks, track referencing tools may be used to link between G-PCC component tracks. For example, TrackReferenceTypeBoxes may be added to a TrackReferenceBox within a TrackBox of a G-PCC track. The TrackReferenceTypeBox may contain, for example, an array of track_IDs that specify the tracks to which the G-PCC track references. To link a G-PCC geometry track to a G-PCC attribute track, the reference_type of the TrackReferenceTypeBox of the G-PCC geometry track may be implemented to identify the associated attribute track. The 4CC of the track reference type may be "gpca". In an embodiment, the referenced track may contain a coded bitstream of G-PCC attribute data.

[0126] If the geometry stream of a G-PCC bitstream contains multiple tiles, each tile or group of tiles may be encapsulated in a separate track, such as a geometry tile track. In an embodiment, the geometry tile track may carry one or more geometry tile TLV units, which may allow direct access to the tiles. The attribute stream of a G-PCC bitstream may contain multiple tiles and be carried in multiple attribute tile tracks.

[0127] G-PCC tile data can be carried in separate geometry and attribute tile tracks within a container. Partial access within the ISOBMFF container of the G-PCC coded stream can be supported. Tiles corresponding to spatial regions within a point cloud scene can be signaled in samples of a time-domain metadata track such as a track having a Dynamic3DSpatialRegionSampleEntry, or in a GPCCSpatialRegionInfoBox box. Thereby, a player and / or a streaming client may be able to extract a set of tile tracks that carry information required to render a specific spatial region or tile within the point cloud scene.

[0128] G-PCC base tracks can carry a TLV encapsulation structure. The TLV encapsulation structure may include (e.g., may include only) a sequence parameter set (SPS), a geometry parameter set (GPS), an attribute parameter set (APS), and tile inventory information. To link a G-PCC base track to a geometry tile track, a track reference having a new track reference type can be defined using a four-character code (4CC) "gccg". Using the new type of track reference, a G-PCC base track can be linked to geometry tile tracks (e.g., each of the geometry tile tracks).

[0129] Geometry tile tracks (e.g., each geometry tile track) can be linked to other attribute G-PCC tile tracks that carry attribute information for respective tiles or tile groups using a track reference tool. The 4CC of these track reference types can be "gpca".

[0130] Alternate tracks may be indicated by an alternate track mechanism (e.g., the alternate_group field of the TrackHeaderBox). In an embodiment, G-PCC component tile tracks containing the same alternate_group value may be different coded versions of the same G-PCC component. Volumetric visual scenes may be coded as alternatives. In such a case, for example, G-PCC tracks that are alternatives to each other may contain the same alternate_group value in their TrackHeaderBoxes.

[0131] A G-PCC component tile track may contain alternatives. In such cases, G-PCC component tile tracks that belong to an alternative group (e.g., all G-PCC component tile tracks) may be referenced by the G-PCC base track and / or the respective G-PCC geometry tile track. In an embodiment, G-PCC component tile tracks that are alternatives to each other may use an alternative grouping mechanism.

[0132] MPEG Dynamic Adaptive Streaming over HTTP (MPEG-DASH), for example, is a delivery format that can dynamically adapt to changing network delivery conditions in order to provide an end user with a video experience (e.g., a better video experience).

[0133] Dynamic HTTP streaming may deliver multimedia content at one or more bit rates that may be available at a server. The multimedia content may include multiple media components (e.g., audio, video, and / or text media components). Different media components may include different characteristics. One or more characteristics of a media component may be described, for example, by a Media Presentation Description (MPD).

[0134] FIG. 8 shows an exemplary MPD hierarchical data model. As shown in FIG. 8, the MPD may describe a sequence of periods (e.g., time intervals). For example, a set of encoded versions of media content components may not change during a period. A period (e.g., each period) may have a start time and a duration associated with the period. A period (e.g., each period) may include one or more adaptation sets (e.g., an AdaptationSet such as Adaptation Set 1 shown in FIG. 8). Adaptation Set, adaptation set, AdaptationSet, and adaptationset may be used interchangeably herein. In an example, the DASH streaming client may be a WTRU, as described herein with respect to FIGS. 1A - 1D. In another example, the DASH streaming client may include a head-mounted device, a head-mounted projector, and / or a heads-up display. In another example, the DASH streaming client may include a 3D television. In another example, the DASH streaming client may include one or more cameras (e.g., high-altitude cameras).

[0135] An adaptation set (e.g., an Adaptation Set, adaptation set, AdaptationSet, or adaptationset) may represent a set of coded versions of one or more media content components that share one or more properties (e.g., the same property), such as, for example, one or more of language, media type, picture aspect ratio, role, accessibility, viewpoint, rating property, etc. In an embodiment, an AdaptationSet may include different bitrates of geometry components and / or attribute components of multimedia content (e.g., G-PCC content). An AdaptationSet may include different bitrates of audio components (e.g., low-quality stereo and / or high-quality surround sound) of multimedia content (e.g., the same multimedia content). In an embodiment, an AdaptationSet (e.g., each Adaptation Set) may include multiple Representations.

[0136] A Representation may describe a deliverable encoded version of one or more media components. Representation and expression may be used interchangeably herein. A Representation may differ from other Representations by, for example, bit rate, resolution, number of channels, and / or other characteristics. A Representation (e.g., each Representation) may contain one or more segments. Attributes of a Representation element (e.g., @id, @bandwidth, @qualityRanking, and / or @dependencyId) may specify (e.g., may be used to specify) one or more properties of a Representation.

[0137] Segments can be retrieved using HTTP requests. Segments (e.g., each segment) can include a URL (e.g., an addressable location on a server). In an embodiment, segments can be downloaded using, for example, an HTTP GET or an HTTP GET with a byte range.

[0138] The DASH client can parse the MPD XML document. For example, the DASH client can select a collection of AdaptationSets (e.g., suitable for the DASH client's environment) based on elements of the AdaptationSet (e.g., the information provided in each of the elements of the AdaptationSet). The client can select a Representation of the AdaptationSet (e.g., within each AdaptationSet). The client can select a Representation based on, for example, the value of the @bandwidth attribute, the client coding capabilities, and / or the client rendering capabilities. The client can download the initialization segment of the selected Representation. The client can access the content (e.g., by requesting the entire segment or a byte range of the segment). The client can continue to consume the media content, for example, when the presentation starts or during the presentation. The client can request a media segment and / or a part of the media segment (e.g., continuously request) during the presentation. The client can play the content according to the media presentation timeline. The client can switch from a first Representation to a second Representation based on, for example, updated information from the client's environment. The client can play the content continuously over, for example, one or more Periods. The media presentation (e.g., consumed by the client in the segment) may end, a period may start, and / or the MPD may be refetched, for example, towards the end of the announced media in the Representation.

[0139] MPEG-DASH descriptors can provide application-specific information about media content. The descriptor element structure can be similar. Descriptor elements can include, for example, an @schemeIdUri attribute that provides a URI for identifying a scheme, an @value attribute, and / or an @id attribute. The element semantics can be specific to the scheme employed. The URI identifying the scheme can be, for example, a URN or a URL. The MPD can provide information on how to use the elements. An application adopting the DASH format can, for example, instantiate the descriptor elements using the scheme information. A DASH application using an element (e.g., a descriptor element) can define a scheme identifier (e.g., in the form of a URI) (e.g., define it first) and can define the value space of the element (e.g., for when the scheme identifier is used). In an example, extended elements and / or attributes can be defined, for example, in a separate namespace for structured data. Descriptors can appear at several levels within the MPD. For example, the presence of an element at the MPD level can indicate that the element is a child of an MPD element. For example, the presence of an element at the AdaptationSet level can indicate that this element is a child element of an AdaptationSet element. For example, the presence of an element at the Representation level can indicate that this element is a child element of a Representation element.

[0140] (e.g., in MPEG-DASH) A bundle can be a set of media components that can be jointly consumed by a decoder instance (e.g., a single decoder instance). A bundle (e.g., each bundle) can contain decoder-specific information and / or can include a media component (e.g., a main media component) that can bootstrap the decoder. PreSelection can, for example, reference, identify, and / or define a subset of the media components within a bundle that can be jointly consumed (e.g., that are expected to be jointly consumed).

[0141] An Adaptation Set that includes a main media component may be referred to as a Main Adaptation Set. Main Adaptation Set, Main Adaptation Set, and Main Adaptation Set (e.g., any variation based on capitalization or composition of an adaptation set (e.g., adaptation set)) may be used interchangeably herein. A main media component may be included in a PreSelection that may be associated with a Bundle. A Bundle (e.g., each Bundle) may include one or more Partial Adaptation Sets. Partial Adaptation Sets may be processed in combination with the Main Adaptation Set.

[0142] Table 4 shows an example of PreSelection element semantics. A PreSelection may be defined, for example, through a PreSelection element, for example, as shown in Table 4. In an example, the selection of a PreSelection may be based on attributes and / or elements that may be included in the PreSelection element.

[0143] [Table 4] Multimedia applications such as virtual reality (VR) and immersive 3D graphics may be implemented using or represented by 3D point clouds, which may enable updated forms of interaction and / or communication with one or more virtual worlds. Static and dynamic point clouds may generate large amounts of information. Efficient encoding algorithms may be used to compress the point cloud information, for example, to reduce storage and / or transmission resource utilization by the point cloud information. For example, a bitstream of compressed dynamic point cloud information may utilize fewer transmission resources than a bitstream of uncompressed information.

[0144] A point cloud application may utilize coding, memory, and / or network resources (e.g., streaming of point cloud data over a network). In an example, the point cloud application may perform live streaming or on-demand streaming of point cloud content depending on, for example, how the content can be generated. The point cloud application may create, process, and / or transmit or receive a large amount of information representing the point cloud. The point cloud application may support adaptive streaming techniques, for example, with respect to varying network capacity and / or other operating conditions, to avoid network overload and / or to provide an optimized viewing experience.

[0145] MPEG-DASH may provide (e.g., be used to provide) adaptive delivery of a point cloud. MPEG-DASH may be implemented using signaling for supporting point cloud media including a point cloud stream. The signaling element may indicate or enable a streaming client to identify point cloud streams within an MPD file and component sub-streams of these point cloud streams. The signaling element may indicate or enable identification of one or more types of metadata that a streaming client may associate with a point cloud component, for example, to enable the streaming client to select a version (e.g., the best version) of the point cloud or point cloud component that may be configured or configurable to be supported by the streaming client.

[0146] Components of the point cloud content may be available in different representations. In an embodiment, the multiple representations (e.g., each of the multiple representations) may represent a different quality level. A streaming client may utilize guidance regarding the different representations (e.g., instructions signaled in an MPD file). For example, the instructions may indicate which set of representations across different components constitutes a particular quality level (e.g., to perform graceful quality degradation). Components of the point cloud content may be divided into multiple tiles. A client may stream specific tile portions (e.g., selected tile portions) of a geometry component (e.g., instead of streaming all point cloud data) based on, for example, bandwidth availability. G-PCC component tile bitstreams may be available in different Adaptation Sets, e.g., an Adaptation Set (e.g., each Adaptation Set) may represent a G-PCC component tile.

[0147] G-PCC media content may include several components, such as geometry and / or attributes. A component (e.g., each component in a plurality of components) may be encoded separately, for example, as a substream of a G-PCC bitstream. Components such as geometry and attributes may be encoded, for example, using a G-PCC encoder. The substreams may be decoded together (e.g., along with metadata), for example, to render a point cloud.

[0148] The elements and / or attributes may be defined, for example, as XML elements and / or XML attributes. The XML elements may be defined, for example, within a separate namespace (e.g., "urn:mpeg:mpegI:gpcc:2020"). The namespace designator "gpcc:" may be used herein, for example, to refer to the separate namespace.

[0149] G-PCC Components may be signaled in a DASH MPD. In an embodiment, a G-PCC component (e.g., each G-PCC component) may be represented in a DASH manifest file (e.g., an MPD file) as a separate Adaptation Set, which may be referred to as a Component Adaptation Set, for example. An Adaptation Set containing geometry information may be a Main Adaptation Set, which may serve as an access point (e.g., a main access point) for G-PCC content, for example. In an embodiment, an adaptation set (e.g., one adaptation set) may be signaled per component per resolution. In an embodiment, the Main Adaptation Set may include an @codecs attribute set to "gpc1".

[0150] The EssentialProperty descriptor may be used with an @schemeIdUri attribute set equal to "urn:mpeg:mpegI:gpcc:2020:component" to identify, for example, the type of G-PCC component in a Component Adaptation Set. The EssentialProperty descriptor may be referred to, for example, as a GPCCComponent descriptor.

[0151] In an embodiment (e.g., at the adaptation set level), a GPCCComponent descriptor (e.g., one GPCCComponent descriptor) may be signaled for each point cloud component (e.g., each point cloud component) present in the Representation of the adaptation set.

[0152] Table 5 shows an example of elements and attributes of a GPCCComponent descriptor. In an example, the @value attribute of a GPCCComponent descriptor may not be present. The GPCCComponent descriptor may include the attributes defined in Table 5.

[0153]

Table 5

[0154]

Table 6

[0155] In an embodiment, the initialization segment of a Representation (e.g., each Representation) may include, for example, a G-PCC parameter set for the Representation and geometry data for the Representation if two or more Representations are signaled in the Main Adaptation Set. Representations of other Component Adaptation Sets (e.g., other Component Adaptation Sets of a point cloud) may list corresponding Representation identifiers from the Main Adaptation Set, for example, using the @dependencyId attribute. Representations in the Main Adaptation Set may be mapped to corresponding Representations in the G-PCC Component Adaptation Set. A media segment of a Representation in a Main Adaptation Set may include, for example, one or more track fragments of a G-PCC track. A media segment of a Representation in a Component Adaptation Set may include, for example, one or more track fragments of the corresponding component track (e.g., at the file format level).

[0156] In an embodiment, the Role descriptor element can be used with values defined for the G-PCC component. For example, one or more geometry components can include the corresponding values of gpcc-geometry, and / or one or more attribute components can include the corresponding values of gpcc-attribute. The EssentialProperty descriptor element (e.g., similar to the EssentialProperty descriptor element described for the example shown in Table 5) can be signaled at the adaptation set level. In an embodiment, the EssentialProperty descriptor element can be signaled (e.g., at the adaptation set level) except for the component_type attribute. The EssentialProperty descriptor element can be signaled, for example, to identify a geometry component and / or an attribute component.

[0157] In an embodiment, for example, when multiple versions of a G-PCC component are encoded using different codecs, the version (e.g., each version) of the multiple versions of the G-PCC component can be signaled in a separate AdaptationSet together with the values of the @codecs attribute set according to the media codec used. Switching between Representations across AdaptationSets of multiple versions of the G-PCC component (e.g., seamless switching) can be supported. Each of the multiple adaptation sets can include a SupplementalProperty descriptor having, for example, @schemeIdURI:mpeg:dash:adaptation-set-switching:2016 set to urn, and / or an @value that is a comma-separated list of AdaptationSet IDs corresponding to other available versions, to indicate that seamless switching between Representations across AdaptationSets of multiple versions of the G-PCC component is supported. In an embodiment, one or more rules for supporting switching across adaptation sets can be applied.

[0158] A G-PCC tile track may be signaled. When multiple tile tracks are present in a G-PCC container, the Main Adaptation Set may include (e.g., include only) the parameter set and tile inventory information from the G-PCC base track. Geometry data and / or attribute data may not be present in the Main Adaptation Set and its Representation. In an embodiment, the @codecs attribute of the Main Adaptation Set may be set to "gpcb," indicating, for example, that the Adaptation Set includes base track data including (e.g., include only) the SPS, GPS, APS, and Tile Inventory information of the G-PCC content.

[0159] A component tile track (e.g., each component tile track) may be signaled in a separate Adaptation Set. A separate Adaptation Set may be referred to as a Tile Component Adaptation Set. When multiple versions of a component of the same tile (e.g., or the same set of tiles) exist and are carried in separate tile tracks, each version may be signaled in a Representation of a Tile Component Adaptation Set. The @codecs attribute of a Tile Component Adaptation Set representing a component tile track of G-PCC media content may be set to "gpt1".

[0160] At the Tile Component Adaptation Set level, the GPCCComponent descriptor can be signaled. In an embodiment, the GPCCComponent descriptor may include an attribute (e.g., an additional attribute) @tile_ids that indicates, for example, a list of tiles present in the tile bitstream. The GPCCComponent descriptor may include (e.g., conditionally include) the XML attribute @attr_index if the component represented by the containing Adaptation Set is a G-PCC attribute component. The @attr_index attribute can, for example, signal the order of G-PCC attribute components in the SPS and / or enable distinguishing G-PCC attribute components when multiple G-PCC attribute components having the same attribute type (e.g., two or more color attributes) are present in the G-PCC content. The GPCCComponent descriptor present at the Tile Component Adaptation Set level may include elements and / or attributes defined in Table 7.

[0161]

Table 7

[0162]

Table 8

[0163] G-PCC component tile tracks that include the same alternate_group value may be signaled in the MPD, for example, as Representations of the Tile Component Adaptation Set.

[0164] The G-PCC descriptor may be signaled. A streaming client may identify (e.g., may be able to identify or may be configured to identify) the type of point cloud component in an AdaptationSet and / or Representation, for example, by checking the GPCCComponent descriptor within the corresponding element. A streaming client may distinguish between different geometry point cloud streams present within the MPD file.

[0165] The G-PCC descriptor may include a SupplementalProperty element having an @schemeIdUri attribute equal to, for example, "urn:mpeg:mpegI:gpcc:2020:gpc". Table 9 shows an example of the attributes of the G-PCC descriptor. In an embodiment, one or more (e.g., at most one) G-PCC descriptors may be present at the Adaptation Set level of the Main Adaptation Set of the G-PCC media.

[0166]

Table 9

[0167]

Table 10

[0168] In an embodiment, a SupplementalProperty element having an @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:tileID" can be (e.g., may be so called) a GPCCTileId descriptor. The GPCCTileId descriptor can be used to distinguish different G-PCC tile streams. In an embodiment, one (e.g., at most one) GPCCTileId descriptor can be signaled and / or present at the adaptation set level of the G-PCC tile media. One (e.g., at most one) GPCCTileId descriptor can be signaled and / or present at the adaptation set level, for example, when the GPCCComponent descriptor is not available at the adaptation set level (e.g., when all G-PCC component data of a tile or a group of tiles is in one track).

[0169] In an embodiment, the @value attribute of the GPCCTileId descriptor may not exist. The GPCCTileId descriptor can include one or more attributes shown in Table 11.

[0170]

Table 11

[0171]

Table 12

[0172] Figure 9 shows an example of using preselection to group G-PCC components in an MPD. Figure 9 shows an example DASH configuration for grouping G-PCC components that may belong to volumetric media (e.g., a single volumetric media) in an MPEG-DASH MPD file.

[0173] Multiple versions of G-PCC media may be signaled. In an embodiment, multiple versions of the same point cloud media may be signaled, for example, using separate PreSelections. PreSelections representing alternative versions of the same geometry-based point cloud media may, for example, include G-PCC descriptors with the same @gpcId value. One or more (e.g., at most one) G-PCC descriptors may exist, for example, at the preselection level. A preselection may be a selectable alternative. The id list of the @preselectionComponents attribute may, for example, include the ID of the Main Adaptation Set, followed by the remaining component Adaptation Set IDs, if the @codecs attribute is set to "gpc1".

[0174] Figure 10 shows an example of using preselection to group multiple versions of a G-PCC component in an MPD. Figure 10 shows an example of a DASH configuration for grouping multiple versions of a G-PCC component that may belong to a single point cloud in an MPEG-DASH MPD file. The grouping / association may be signaled, for example, using a preselection descriptor. Table 13 shows an example of using preselection to signal multiple versions of a G-PCC component in an MPD.

[0175] [Table 13-1]

[0176] [Table 13-2]

[0177] [Table 13-3]

[0178]

Table 13-4

[0179]

Table 13-5

[0180] In an embodiment, G-PCC Tile Preselection may be implemented. When G-PCC content is carried using multiple tile tracks, the Main Adaptation Set may signal the G-PCC base track data. The Tile Component Adaptation Set may signal the G-PCC geometry and / or attribute tile track data.

[0181] G-PCC Tile Preselection can be signaled in MPD using the PreSelection element described herein. In an example, the @codecs attribute of Preselection can be set to "gpt1", indicating, for example, that the Preselection media is a set of geometry-based point cloud tiles. Preselection can be signaled using the PreSelection element within the Period element, as described herein. Preselection can be signaled using the Preselection descriptor at the Tile Component Adaptation Set level.

[0182] The PreSelection element may contain a list of IDs of the @preselectionComponents attribute. The @preselectionComponents attribute ID list of G-PCC Tile Preselection may include the Tile Component Adaptation Set and the corresponding attribute Tile Component Adaptation Set ID that follows it. The Representation of the Main Adaptation Set corresponding to the Representation of the selected geometry Tile Component Adaptation Set can be identified, for example, using the @dependencyId attribute signaled in the Representation of the Adaptation Set.

[0183] A G-PCC Tile Preselection (e.g., each G-PCC Tile Preselection) may contain one or more GPCCTileId descriptors, which may enable identification of the tiles referenced in each preselection. If no GPCCTileId descriptor is present, the tiles belonging to the G-PCC Tile Preselection may be identified by finding the Geometry Tile Component Adaptation Set from the ID list of the @preselectionComponents attribute and checking the list of tile IDs from the GPCCComponent descriptors present in the Geometry Tile Component Adaptation Set.

[0184] FIG. 11 shows an example of G-PCC content with multiple tile tracks. FIG. 11 may be an exemplary DASH configuration. The G-PCC content may include a geometry component and one or more attribute components (e.g., three attribute components). In this example, the G-PCC bitstream includes six tiles grouped into two tile sets. The first tile set includes tiles 1, 2, and 3, and the second tile set includes tiles 4, 5, and 6. The components of each tile set may be available in two different versions (e.g., encoded at different qualities). The component versions of a tile set (e.g., each component version) may be carried in a separate G-PCC tile track within the ISOBMFF container file. The MPD file may include a Tile Component Adaptation Set for each component of the two tile sets. The Tile Component Adaptation Set (e.g., each Tile Component Adaptation Set) may include two representations (e.g., one for each version of the component). Two preselections may be used in the MPD to signal the two tile sets present in the G-PCC bitstream.

[0185] Table 14 shows an example of a DASH MPD file signaling G-PCC content with multiple tile tracks with a Preselection descriptor.

[0186] [Table 14-1]

[0187] [Table 14-2]

[0188] [Table 14-3]

[0189] [Table 14-4]

[0190] [Table 14-5] In an embodiment, media data may be signaled using separate PreSelections, e.g., if multiple point cloud media are available. A PreSelection representing geometry-based point cloud media data may include a G-PCC descriptor with a unique @gpcId value. One or more (e.g., at most one) G-PCC descriptors may be present, e.g., at the preselection level. There may be an ID of the main adaptation set, an ID (e.g., the first ID) in the list of adaptation set IDs in the @preselectionComponents attribute, and / or an ID of an AdaptationSet corresponding to (e.g., subsequent) point cloud components. The point cloud may be identified, e.g., using a unique value of the @gpcId attribute, as may be defined, e.g., within the G-PCC descriptor.

[0191] G-PCC tile groups may be signaled. In an embodiment, tile bounding box information may be signaled (e.g., using a GPCCTileInventory descriptor), for example, if there are multiple tiles in a geometry-based point cloud. The GPCCTileInventory descriptor may be, for example, a SupplementalProperty element with an @schemeIdUri attribute (e.g., set to "urn:mpeg:mpegI:gpcc:2020:gptl"). The GPCCTileInventory descriptor may be present, for example, at the adaptation set level of the Main Adaptation Set of G-PCC media if the G-PCC media is tiled. Table 15 shows an example of elements and attributes of a GPCCTileInventory descriptor.

[0192] [Table 15] Table 16 shows an example of an XML schema for the GPCCTileInventory descriptor. The data types of the various elements and attributes of the GPCCTileInventory descriptor may be defined according to an XML schema such as, for example, the example schema shown in Table 16.

[0193] [Table 16] A client may select (e.g., initially select) a tile ID from tile inventory bounding box information present in the MPD, for example, if the client is going to stream tiled G-PCC component data from a server. In an embodiment, the G-PCC component with the selected tile_id may be streamed to the client.

[0194] Dynamic G-PCC Tile Inventory information may be signaled. If the parameter set data and / or tile inventory information is changing dynamically, information about such changes may be carried in samples of the G-PCC base track. In an example, where there are multiple tiles in a geometry-based point cloud and the bounding box information of the tiles is changing dynamically, the tile bounding box information may be carried (e.g., together with the parameter set data) in the Media Segment of the Representation of the Main Adaptation Set.

[0195] The spatial region may be static. The characteristics of the spatial region and / or the mapping between the region and the G-PCC tiles may be signaled (e.g., using a GPCC3DRegions descriptor) if, for example, the 3D spatial region is static. The 3D spatial region may be static if, for example, the position and dimensions of the region (e.g., each region) do not change over the presentation time. The GPCC3DRegions descriptor may be, for example, a SupplementalProperty element with a @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:gpsr". The GPCC3DRegions descriptor (e.g., a single GPCC3DRegions descriptor) may be present at, for example, the adaptation set level and / or the representation level in the main G-PCC track, or at the pre-selection level of the geometry-based volumetric media content.

[0196] The @value attribute of the GPCC3DRegions descriptor may not be present. The GPCC3DRegions descriptor may contain elements and / or attributes (e.g., as specified in Table 17). Table 17 shows examples of elements and attributes associated with the GPCC3DRegions descriptor.

[0197] [Table 17] The data types of the various elements and attributes of the GPCC3DRegions descriptor may be defined by a schema such as the XML schema shown in Table 18. Table 18 shows an example of an XML schema for the GPCC3DRegions descriptor.

[0198] [Table 18] In an embodiment, the properties of a spatial region and / or the mapping between the spatial region and the corresponding AdaptationSet of a G-PCC component may be signaled (e.g., using a GPCC3DRegions descriptor), e.g., when the 3D spatial region is static and tile inventory information is not available. The GPCC3DRegions descriptor may, for example, be a SupplementalProperty element with an @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:gpsr". A GPCC3DRegions descriptor (e.g., a single GPCC3DRegions descriptor) may be present, for example, at the adaptation set level and / or representation level in the main G-PCC track, or at the pre-selection level for geometry-based volumetric media content.

[0199] The @value attribute of the GPCC3DRegions descriptor may not be present. The GPCC3DRegions descriptor may include elements and attributes (e.g., as specified in Table 19). Table 19 shows example elements and attributes of the GPCC3DRegions descriptor.

[0200] [Table 19] The data types of the various elements and attributes of the GPCC3DRegions descriptor may be defined according to a schema, such as an XML Schema. Table 20 shows an example of an XML Schema for the GPCC3DRegions descriptor.

[0201] [Table 20] In an embodiment, the mapping between a spatial region and a corresponding AdaptationSet of a G-PCC component may be signaled using a GPCC3DRegionId descriptor, for example, if the 3D spatial region is static. The descriptor may be a SupplementalProperty element with an @schemeIdUri attribute equal to "urn:mpeg:mpegI:gpcc:2020:gp3rid". A single GPCC3DRegionId descriptor may be present at the adaptation set level of a G-PCC component (e.g., each G-PCC component). A GPCC3DRegionId may not be present, for example, if a gpsr.spatialRegion@asIds attribute is present in the GPCC3DRegions descriptor.

[0202] The @value attribute of the GPCC3DRegionId descriptor may not be present. The GPCC3DRegionId descriptor may contain one or more attributes shown in Table 21.

[0203] [Table 21] The data type of the attribute may be as provided in an XML Schema. The XML Schema for the GPCC3DRegionID descriptor is shown below. This schema includes the namespace urn:mpeg:mpegI:gpcc:2020 and may be expressed as an XML Schema specified in Table 22.

[0204] [Table 22] In an embodiment, the mapping between a spatial domain and a corresponding AdaptationSet of a G-PCC component may be signaled using a GPCCComponents descriptor, e.g., if the 3D spatial domain is static. The GPCCComponent descriptor may include elements and attributes defined in Table 23. The GPCC3DRegionID descriptor may not be present, e.g., if the @region_Id attribute is present in the GPCCComponents descriptor.

[0205] [Table 23] An example of an XML schema for a GPCCComponent descriptor is shown in Table 24 below.

[0206] [Table 24] In an embodiment, one or more spatial regions may be dynamic. In the case of a 3D division that may be dynamic, timed metadata tracks for signaling the position and / or dimensions of the 3D regions (e.g., each 3D region) on the presentation timeline may be carried in a separate AdaptationSet with a single representation. The timed metadata tracks may be associated (e.g., linked) to the main G-PCC Adaptation Set. Attributes used may include an @associationId attribute and an @associationType value containing the 4CC "gpdr" of the corresponding AdaptationSet or Representation.

[0207] The streaming client behavior may be based on signaling, e.g., signaling of one or more descriptors. The DASH client may be guided, for example, by the information provided in the MPD. The following is an example of client behavior for streaming geometry-based point cloud compressed content using, for example, the signaling embodiments disclosed herein. Exemplary client behavior may assume, for example, that the association of the component AdaptationSet to the main point cloud AdaptationSet is signaled using the G-PCC descriptor.

[0208] The streaming client may issue, for example, an HTTP request having a destination set to the content server (e.g., issue it first). The streaming client may download the MPD file from the content server. The client may parse the MPD file, for example, to generate a corresponding in-memory representation of the XML elements within the MPD file.

[0209] The streaming client may check the PreSelection element at the period level (e.g., by setting the @codecs attribute to "gpc1" or "gpt1") to identify the available G-PCC media content within the Period.

[0210] The AdaptationSet(s) belonging to the point cloud content represented by the PreSelection element (e.g., all AdaptationSets) may be identified, for example, by checking the ID list within the @preselectionComponents attribute of the PreSelection. The Main Adaptation Set may contain an @id value equal to the @id value of the first ID in the list.

[0211] The streaming client can, for example, identify the number of unique point clouds by checking the G-PCC descriptor of the AdaptationSet and / or group AdaptationSets with the same @gpcId value in the G-PCC descriptor as versions of the same content.

[0212] The streaming client can identify the components of the point cloud (e.g., by checking the GPCCComponent descriptors of the remaining AdaptationSets referenced in the ID list of the @preselectionComponent attribute) and can map the components (e.g., each component) to its corresponding AdaptationSet. In an embodiment, more than one point cloud component may be present in an AdaptationSet.

[0213] A group of AdaptationSets having an @gpcId value present in the G-PCC descriptor corresponding to the desired content may be selected from the ID list of the @preselectionComponent attribute, for example, based on the point cloud content that the user may be interested in streaming. The streaming client may, for example, select an AdaptationSet group having a supported version (e.g., supported resolution) if there are multiple PreSelection descriptors with the same @gpcId value. For example, if there are no multiple PreSelection descriptors with the same @gpcId value, only one AdaptationSet group may be selected.

[0214] The client may start streaming the point cloud by, for example, downloading an initialization segment for the Main Adaptation Set, which contains a parameter set for initializing the G-PCC decoder. The initialization segments of the coded component streams may be downloaded and / or cached in memory.

[0215] The streaming client may start downloading temporally synchronized media segments from the Main Adaptation Set and / or Component Adaptation Set (e.g., in parallel via HTTP). In an embodiment, the downloaded segments may be stored in an in-memory segment buffer. The temporally synchronized media segments may be removed from their respective buffers of these media segments and / or concatenated with their respective initialization segments of these media segments.

[0216] The media container (e.g., ISO Base Media File Format (ISOBMFF)) may be parsed, for example, to extract elementary stream information and to structure the G-PCC bitstream, and the bitstream may be passed to a G-PCC decoder.

[0217] Client behavior for streaming G-PCC media having multiple tiles may be implemented, for example, using MPD signaling as described herein. The client (e.g., the streaming client) may issue an HTTP request and / or download an MPD file from a content server. The client may parse the MPD file to generate a corresponding in-memory representation of the XML elements within the MPD file.

[0218] The client may check, at the period level, an AdaptationSet element whose @codecs attribute is set to "gpcb" and a PreSelection element whose @codecs attribute is set to "gpt1" to identify available G-PCC tiled media content within a Period, for example.

[0219] When there is G-PCC tiled media content, the client can identify the tiles of interest in the point cloud bitstream, for example, based on the client's current viewport. The client can parse the GPCC3DRegions descriptor and / or find each tile within the viewport. If the 3D segmentation is dynamic, a Media Segment of the Time Domain Metadata Adaptation Set that can convey the position and / or dimensions of the 3D regions (e.g., each 3D spatial region) on the presentation timeline can be downloaded. The 3D regions within the viewport can be identified. Each tile belonging to the region can be identified.

[0220] When a tile of interest is found, the client can select the PreSelection element having the tile, for example, by parsing the GPCCTileId descriptor present within the PreSelection element (e.g., each PreSelection element). The @tile_Ids attribute within the GPCCTileId descriptor can list the available tiles. A preselection element having the tile of interest can be selected. Preselections (e.g., other Preselections) can be ignored.

[0221] If the GPCCTileId descriptor is not available, the tiles present within the PreSelection element can be identified by, for example, finding the Geometry Tile Component Adaptation Set from the id list of the @preselectionComponents attribute and finding the list of tile IDs from the GPCCComponent descriptor present within the Geometry Tile Component Adaptation Set. If a tile of interest is present within the PreSelection element, the preselection can be selected by the client.

[0222] A group of Tile Component Adaptation Sets to be used to download a Media Segment from a selected Preselection may be identified from the ID list of the @preselectionComponent attribute. In an embodiment, the @preselectionComponents list may include geometry Tile Component Adaptation Set IDs. The @preselectionComponents list may include remaining component Tile Component Adaptation Set IDs. The ID of the Main Adaptation Set may not be present in the @preselectionComponents list. For example, the ID of the Main Adaptation Set may be identified using the @dependencyId attribute present in the Representation of the Geometry Tile Component Adaptation Set.

[0223] The client may start streaming the point cloud by, for example, downloading the Initialization Segment from the Main Adaptation Set, which may include a parameter set for initializing the G-PCC decoder.

[0224] The Initialization Segment for the coded component stream (eg, if present) may be downloaded and / or cached in memory.

[0225] A streaming client may download time-aligned Media Segments from geometry Tile Component Adaptation Sets and / or associated attribute Tile Component Adaptation Sets. The download may be parallelized over HTTP, and the downloaded segments may be stored in an in-memory segment buffer.

[0226] The time-aligned Media Segments may be removed from their respective buffers and / or concatenated with their respective Initialization Segments.

[0227] A media container (e.g., ISOBMFF) can be parsed, for example, to extract elementary stream information. The media container can be structured, and the resulting bitstream can be passed to a G-PCC decoder.

[0228] Many embodiments are described herein. Features of the embodiments may be provided alone or in any combination across various claim categories and types. Furthermore, an embodiment may include one or more of the features, devices, or aspects described herein, alone or in any combination across various claim categories and types, such as, for example, any of the following:

[0229] A decoder, such as exemplary decoder 300, configured to receive, decode, and interpret signals (e.g., as described herein) indicating elements, attributes, and metadata associated with point cloud components; identify point cloud streams and component sub-streams of these point cloud streams in a Media Presentation Descriptor (MPD); identify versions of the point cloud and / or components of this point cloud; decode the MPD to identify a main adaptation set and other adaptation sets and identify G-PCC components in Geometry-Based Point Cloud Compression (G-PCC) content; decode the MPD to identify adaptation sets or point cloud components in a representation; decoding the MPD to identify one or more versions of the G-PCC media; decoding the MPD to identify one or more G-PCC tile groups; decoding the MPD to identify one or more tile IDs of G-PCC components in the adaptation set; decoding the MPD to identify one or more characteristics of spatial regions and mappings between these regions and G-PCC tiles, characteristics of spatial regions and mappings between these regions and corresponding adaptation sets of G-PCC components, and / or mappings between spatial regions and corresponding adaptation sets of G-PCC components; decoding the MPD to identify timed metadata tracks for dynamic spatial regions, etc.

[0230] Decoding tools and techniques including one or more of entropy decoding, inverse quantization, inverse transform, and differential decoding used to enable the methods described herein in a decoder.

[0231] A decoder, such as exemplary decoder 200 configured to do the following, generating, decoding, and transmitting a signal (e.g., as described herein) indicative of elements, attributes, and metadata associated with a point cloud component; encoding the MPD to indicate a point cloud stream and component sub-streams of these point cloud streams; encoding the MPD to support identification of geometry-based point cloud compression (G-PCC) components in G-PCC content; encoding the MPD to support identification of the type of point cloud component in an adaptation set or representation; encoding the MPD to identify one or more pre-selections; encoding the MPD to support identification of one or more versions of G-PCC media; encoding the MPD to support identification of one or more G-PCC tile groups; encoding the MPD to support identification of one or more tile IDs of G-PCC components in an adaptation set; encoding the MPD to support identification of one or more characteristics of a spatial region and the mapping between these regions and G-PCC tiles, the characteristics of the spatial region and the mapping between these regions and the corresponding adaptation set of G-PCC components, and / or the mapping between the spatial region and the corresponding adaptation set of G-PCC components; decoding the MPD to identify a time-domain metadata track of a dynamic spatial region; and so on.

[0232] Decoding tools and techniques including one or more of entropy coding, inverse quantization, inverse transform, and differential coding used in an encoder to enable the embodiments described herein.

[0233] For example, a syntax element inserted into signaling to enable identification of an instruction associated with a decoder executing any of the embodiments described herein.

[0234] For example, a syntax element inserted into signaling to enable an encoder to generate or encode an instruction associated with executing any of the embodiments described herein.

[0235] A bitstream or signal may include one or more of the described syntax elements or variations of these syntax elements associated with executing any of the embodiments described herein.

[0236] A method, process, apparatus, medium storing instructions, medium storing data, or signal, or variations thereof, for creating and / or transmitting and / or receiving and / or decoding a bitstream or signal including one or more of the described syntax elements.

[0237] A method, process, apparatus, medium storing instructions, medium storing data, or signal for creating and / or transmitting and / or receiving and / or decoding according to any of the embodiments described herein.

[0238] A TV, set-top box, mobile phone, tablet, or other electronic device that performs adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, according to any of the embodiments described herein.

[0239] A TV, set-top box, mobile phone, tablet, or other electronic device that performs adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, according to any of the embodiments described herein, and displays the resulting image (e.g., using a monitor, screen, or other type of display).

[0240] Select a channel (e.g., using a tuner) to receive a signal including a symbolized image, and perform adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, according to any of the embodiments described herein, in a TV, set-top box, mobile phone, tablet, or other electronic device.

[0241] Wirelessly receive (e.g., using an antenna) a signal including a symbolized image, and perform adaptive streaming of geometry-based point clouds, such as point cloud component sub-streams in a point cloud streaming service, according to any of the embodiments described herein, in a TV, set-top box, mobile phone, tablet, or other electronic device.

[0242] Features and elements are described above in a particular combination, but those skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. Further, the methods described herein can be implemented in a computer program, software, or firmware incorporated into a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, magnetic media such as read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor associated with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.< / maximum> < / minimum>

Claims

1. A coding device, a processor, receiving a Media Presentation Description (MPD) file from a content server; determining, from the MPD file, a Geometry-based Point Cloud Compression (G-PCC) adaptation set, wherein the G-PCC adaptation set is an adaptation set associated with a G-PCC component; determining a G-PCC tile identifier associated with a tile, wherein the G-PCC tile identifier is a GPCCComponent descriptor, which is associated with the G-PCC adaptation set when the GPCCComponent descriptor is signaled at the adaptation set level; a GPCCTileID descriptor associated with the G-PCC adaptation set when all G-PCC components of the tile are available within one track, the determination being made from; using the G-PCC tile identifier associated with the tile to request the G-PCC component; receiving the G-PCC component, a coding device comprising a processor configured to perform the above.

2. The coding device according to claim 1, wherein the GPCCComponent descriptor is signaled for each point cloud component present in a set of representations associated with the G-PCC adaptation set.

3. The coding device according to claim 1, wherein the GPCCComponent descriptor includes information associated with a geometry point cloud component present in the representation of the G-PCC adaptation set.

4. The coding device according to claim 1, wherein the GPCCComponent descriptor includes a list of component type, attribute type, attribute index, and G-PCC tile identifier.

5. The coding device according to claim 1, wherein the processor is configured to determine a GPCC descriptor indicating a point cloud stream present in the MPD file, and the GPCC descriptor is signaled at the adaptation set level.

6. The coding device according to claim 5, wherein the GPCC descriptor is signaled at a preselection level using a preselection element within a period element. **Claim 7** The coding device according to claim 1, wherein the G-PCC adaptation set includes one or more representations. **Claim 8** The coding device according to claim 7, wherein the one or more representations include at least one of bitrate, resolution, number of channels, or quality level. **Claim 9** The coding device according to claim 1, wherein the GPCC TileID descriptor is used to distinguish different G-PCC tile streams. **Claim 10** The coding device according to claim 1, wherein the GPCC TileID descriptor is signaled at the adaptation set level or the preselection level. **Claim 11** A method implemented by a method, comprising: receiving, from a content server, a Media Presentation Description (MPD) file; determining, from the MPD file, a Geometry-based Point Cloud Compression (G-PCC) adaptation set, wherein the G-PCC adaptation set is an adaptation set associated with a G-PCC component; determining a G-PCC tile identifier associated with a tile, wherein the G-PCC tile identifier is a GPCC Component descriptor, which is associated with the G-PCC adaptation set when the GPCC Component descriptor is signaled at the adaptation set level; and a GPCC TileID descriptor, which is associated with the G-PCC adaptation set when all G-PCC components of the tile are available within one track, requesting the G-PCC component using the G-PCC tile identifier associated with the tile; and receiving the G-PCC component. **Claim 12** The method according to claim 11, wherein the GPCC Component descriptor is signaled for each point cloud component present in a set of representations associated with the G-PCC adaptation set. **Claim 13** The method according to claim 11, wherein the GPCC Component descriptor includes information associated with a geometry point cloud component present in the representation of the G-PCC adaptation set.

14. The method according to claim 11, wherein the GPCC Component descriptor includes a list of a component type, an attribute type, an attribute index, and a G-PCC tile identifier.

15. The method according to claim 11, further comprising determining a GPCC descriptor indicating a point cloud stream present in the MPD file, wherein the GPCC descriptor is signaled at an adaptation set level.

16. The method according to claim 15, wherein the GPCC descriptor is signaled at a preselection level using a preselection element within a period element.

17. The method according to claim 11, wherein the G-PCC adaptation set includes one or more representations.

18. The method according to claim 17, wherein the one or more representations include at least one of a bitrate, a resolution, a number of channels, or a quality level.

19. The method according to claim 11, wherein the GPCC Tile ID descriptor is used to distinguish different G-PCC tile streams.

20. The method according to claim 11, wherein the GPCC Tile ID descriptor is signaled at the adaptation set level or the preselection level.

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